From 712c00d66a342a3ed375df41c3df7d3d2abad2c0 Mon Sep 17 00:00:00 2001 From: Stefan Roesch Date: Fri, 18 Nov 2022 16:52:05 -0800 Subject: mm: add bdi_get_min_bytes() function This adds a function to return the specified value for min_bytes. It converts the stored min_ratio of the bdi to the corresponding bytes value. This is an approximation as it is based on the value that is returned by global_dirty_limits(), which can change. The returned value can be different than the value when the min_bytes value was set. Link: https://lkml.kernel.org/r/20221119005215.3052436-11-shr@devkernel.io Signed-off-by: Stefan Roesch Cc: Chris Mason Cc: Jens Axboe Signed-off-by: Andrew Morton --- include/linux/backing-dev.h | 1 + mm/page-writeback.c | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index ea6c993433d5..8e04567727e6 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -105,6 +105,7 @@ static inline unsigned long wb_stat_error(void) /* BDI ratio is expressed as part per 1000000 for finer granularity. */ #define BDI_RATIO_SCALE 10000 +u64 bdi_get_min_bytes(struct backing_dev_info *bdi); u64 bdi_get_max_bytes(struct backing_dev_info *bdi); int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio); int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 20ae9adeb22f..c47824464f4c 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -740,6 +740,11 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio) } EXPORT_SYMBOL(bdi_set_max_ratio); +u64 bdi_get_min_bytes(struct backing_dev_info *bdi) +{ + return bdi_get_bytes(bdi->min_ratio); +} + u64 bdi_get_max_bytes(struct backing_dev_info *bdi) { return bdi_get_bytes(bdi->max_ratio); -- cgit